几种保护性耕作措施在黄土高原旱作农田的实践

Dry farmland practice involving multi-conservation tillage measuresin the Loess Plateau

  • 摘要: 自2001年起, 甘肃农业大学的研究者在甘肃省定西市安定区李家堡镇布设了不同保护性耕作措施下春小麦→豌豆和豌豆→春小麦轮作系统的定位试验, 以研究免耕不覆盖(NT)、传统耕作秸秆还田(TS)、免耕秸秆覆盖(NTS)、传统耕作地膜覆盖(TP)和免耕地膜覆盖(NTP)等保护性耕作措施在黄土高原旱作农田生态系统中的效应。本文就近10年依托该试验获取的相关研究结果进行综述, 重点阐述特定土壤、气候、农作制度下土壤理化性状、土壤微生物及其酶活性、土壤温室气体排放、作物生理生态等对上述几种保护性耕作措施的响应。初步得到免耕秸秆覆盖措施有助于形成良好的土壤结构、减少土壤侵蚀、改善土壤持水特性、提高土壤养分利用效率、改善土壤微生物区系、增强作物光合效能、增加作物产量等结论, 对筛选出当地适宜的耕作模式、改善区域土壤质量、促进农业可持续发展有重要意义。在此基础上, 提出目前该项研究存在的问题和今后重点关注的方向: 1)保护性耕作土壤碳循环机理; 2)覆盖方式的创新; 3)温室气体排放测量方法的改进与完善。

     

    Abstract: An experiment was set up since 2001 to study the effects of a series of conservation tillage measures on the Loess Plateau farmland ecosystem. The studied tillage measures included non-tillage without mulching (NT), conventional tillage with straw incorporation (TS), non-tillage with straw mulching (NTS), conventional tillage with plastic film mulching (TP) and non-tillage with plastic film mulching (NTP). The study was carried out by researchers from Gansu Agricultural University in Lijiabu Town, Dingxi City, Gansu Province. Two sequences of wheat/peas rotation system were adopted, wheat→ peas and peas → wheat, under different conservation tillage systems. The experiment was significant for screening appropriate local farming methods to improve regional soil quality and promote sustainable agricultural development. This paper summarized the key findings of the experimental study. It also discussed the response of soil physical and chemical properties, soil microbial activities, greenhouse gas emissions, crop physiology and ecology to different conservation tillage systems under specific soil, climate and farming system. The conclusions were as follows: NTS measure contributed to the formation of good soil structure, reduced soil erosion, improved soil water retention characteristics, improved soil nutrient use efficiency, enhanced soil microbial flora, enhanced crop photosynthetic efficiency and increased crop yield. On this basis, the identified problems and proposed future directions were: 1) soil carbon cycle mechanisms under conservation tillage; 2) innovation of coverage modes; 3) improvements in greenhouse gas emission measurement methods.

     

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